Japanese knotweed
This species is prohibited under Michigan law; forms dense thickets that shade out natives; rhizomes can damage pavement; extremely difficult to eradicate; spread by flood waters.
Photo credit: Nisa Karimi, Wisconsin Department of Natural Resources
Bohemian knotweed
Hybrid cross between Japanese knotweed (Polygonum cuspidatum) and Giant knotweed (Polygonum sachalinensis).
Photo credit: Robert Vidéki, Doronicum Kft., Bugwood.org
Giant knotweed
Hybridizes with Japanese knotweed and silver lace vine (P. baldschuanicum).
Photo credit: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
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